Power hammer



July 21, 1953 POWER HAMMER Filed Deo. 5, 1949 Ulm! ,2s i w@ {wsu-rop.' HARRY E. Gmso bvs-W l QHf/ A'rfonnss H. E. GIBSON .I 2,646,100

Patented July 21, 1953 UNITED STATES PATENTy OFFICE POWER HAMMER Harry E. Gibson, Muskegon, Mich. Appxicationnecmber 5, 1949, serial No. 131,221

4 claims. (01453-21) l This invention relates to a power hammer which is used in practice in sheet metal joint forming, and with which a rapid forming of a uniform joint may be made between sheet metal parts which are required in many different l structures, the connected sheet metal parts bemg located in .planes at an angle to each other and most frequently substantially at right angles to each other.

The present invention is directed to/imfprovements in the joint forming device disclosed in my pending application for patent, Ser. No. 40,672,

led July 26, 1948, now abandoned. In the present invention the forceof the hammering movement is provided positively withoutv the necessity of loading any springv which, upon its release supplies the hammering force, springs being eliminated and the immediate hammer given momentum 4byia direct operation of a rapidly rotating and specially constructed actuator, the hammer being withdrawn and projected once in each complete rotation of the actuator which is mounted on a shaft and is rapidly driven. With the structure a rapidsuccession of hammer blows are delivered 'so that the bending and' forming and hammering of the sheet metal parts which are processed takes place progressively as the tool is manually moved along the sheet lmetal members, adjacent edge portion on which are bent and interlocked to formfthe desired joint.

The hammerablowlspare of equal strength and the joint or seam is made of a substantially uniform e quality throughout its length.

An understanding of the invention maybe had from the following description, taken in connection with the accompanying drawing, in which Fig. 1 is an elevation partly in vertical section of the metal joint power hammer tool of my in.

vention, the tool being shown vertically positioned and the mechanism at the lower portion thereof being in transverse vertical section.

Fig. 2 is a fragmentary elevation of the hammer actuator with the associated means on the hammer in section, when it has been withdrawn by the actuator farthest away from the work which is being done, and,

, Fig. 3 is a similar view of the relative positions of such parts when the hammer has been projected toward the Work which it is to accom-Y plish, the actuator having moved rotatively a short distance beyond the position lshown in Fig. 2.

Like reference characters refer to like parts in the different figures of the drawing.

Within the housing I at an end of the enclos- 2 ing body or casing of the machine an electric motor 2 is located, the shaft 3 of which, at its outer end, is formed with parallel pinion teeth meshing with a gear 4 at an end of a short shaft 5, the axis of which is parallel to the axis of the motor shaft and which is mounted in suitable bearings at opposite end portions and which between its ends carries an actuator 6. The actuator '6 is of a cylindrical form and has around it between its ends a groove 'I. The major portion l of the groove is in the same plane, but at one groove I is narrowed at 1a at the free end portion of the projection 8 as shown.

A shaft IIJ is mounted for a limited longitudinal movement-at a side of the actuator, its axis being parallel to the axis'of the shafts 3 and 5. The outer portion I 0a of the shaft II] is interiorly bored lto provide a cylindrical axial opening, such portion of the shaft extending from its outer end nearly to a collar II, integral with or permanently secured toy the shaft I0, which is forr'n'ed with beveled orv inclined upper or lower faces in correspondence with similar beveled inclined upper or lower sides of the groove 'I in the actuator. The collar I I extends 'into the groove 1.

y The outer end portion of the axially bored section Illa of the shaft I0 is interiorly threaded to receive a nut I 2 as shown in Fig. 1. The hammer head I3 is connected with a rod I4 which extends axially and freely through the nut I 2, its inner end being screw threaded and having a member I5 screw connected thereto and adjustf able thereon, between the outer end of which and the inner end of the nut I2 a short coiled compression spring I is located around the rod I4. The member I5 is free to move longitudinally within the axial opening of the portion Illa of the shaft I0. The shoe I1 together with head I3 and other parts adjacent are like those shown in my prior application, reference to which is made above. The enclosing housing I8 in which the several shafts are located and mounted, the shaft I 0 at its outer portion extending beyond said housing, is made up of suitable sections for convenience in assembling as shown, connected together, and at one side thereof a handle I9 for grasping by the hand is permanently secured and extends outwardly therefrom, to which wires leading to its motor 2 are carried through a suitable insulation covered cable 20 to supply the motor with electric current. l Y

In the operation, the actuator 6 is rotated at a relatively high speed but at a reduced speed compared to the revolutions per minute of the motor shaft 3. The shaft l upon the rotation of the actuator 6Y in the directionindicated by the arrows, onl each revolution thereof brings the camside 8a of the cam projection 8 to the collar Il whereupon the projection 8 moves the collar to substantially the position shown in Fig,.2.. On the continued movement of the actuator inthe direction indicated, the curved side or; edge: of.'

the recess 9 engaging said collar.. becausepf the high rotative speed, throws said collar* and the attached shaft and the hammer I3fwithrco1f'` siderable force at the outer end thereof from the position shown inFig. 2 to thatshown in Fig, 3, the projection 8- moving. awayV from the edge of theA Collar El which extends intothe groove I. The momentum of the head 3, the rod I4 to which it is connected andthe member 1.5causes a quick and sharp blow. to-be struck by the head I3 upon the work which isbeing processed. Such blow is cushionedby the spr-ing IB and after i outer end, lsaid hammer having a rod passing through said nut, a member located within the shaft opening screw connected tc the inner end of the rod, and compression spring means bethe blow is, struck and-the. work has been done bythat particular stroke of the hammer, the head is slightly withdrawn from the work until, on the next succeeding` rotation of-.the shaft 5 and the actuator connected thereto, the operation is-repeated;

With the structuredescribed no spring is compressed on the inward movement of the shaft I0 to store power which, when it` is released, furnishes the motivel power `forv the hammering stroke. This isL of. great advantage in the apparatus asrthe driving motor isfnot' periodically, at very close intervals, subjected to4 the load which it would have to take care ofv with each hammer stroke. The structure is simplied, made more accurate and certain in operation and the apparatus is more durable in operation sol that its life of servicev is lengthened.

The invention is-dened in the appended claims and is to be considered comprehensive of all .forms of structure coming within their scope.r

tween. said nut and member at their adjacent ends.

Z.' In a` tool of the class described, a support, ahhammer shaft reciprocably mounted on the support", a hammer at an end of the shaft, a connection between the hammer and shaft comprising, means for positively moving the hainmer away from the support and yieldable means for-retracting the hammer, and means for rapidly reciprocating said hammer shaft.

3. 'Ihe` elements of claim 1 combinedy with means for adjusting the tension of said yieldabie means. n

4. In a tool of the class described, a support, a hammer shaft reciprocably mounted on said support, a hammer at an end of said shaft outside of'said support, an annular collar on said shaft, a circularv cam rotatably mounted on. said support adjacent said shaft, means for rotating said cam, and an annular cam'groove in. said cam, said collar extending into said cam groove and said-cam groove being on the order of twice as wide as the thickness of said collar, and a connection between saidl hammer shaft and hammer comprising, means for'positively moving the hammer away from the support and yieldable means for retracting the hammer.

HARRY E. GIBSON.

References Cited-in the le of this patent UNITED STATES PATENTS Number Name Date 901,276 Betts: Oct. 13, 1908 1,858,169 Pesola May 10, 1932 1,924,946 Kott Aug. 29, 1933 2,051,053 Morris Aug. 18, 1936 FOREIGN PATENTS Number Country Date 5,697 GreatBritain of 1894 

